There presently exists random access audio storage and playback apparatus. One embodiment of such apparatus is a CD ROM which employs a conventional compact disk and disk reader. CD ROMs have a number of disadvantages including their inherent read-only qualities, mechanical complexity and relatively high cost. Portable CD ROM equipment is not presently commercially available.
U.S. Pat. No. 4,636,876 describes the use of speech compression in an audio digital recording and playback system.
U.S. Pat. No. 5,059,126 describes an interactive CD based audio system employing a bar-code reader as a selector input.